1. Field of Invention
The present invention relates to a combined foot operated mechanism for controlling the acceleration and braking of a motor vehicle with a single control element.
2. Discussion of Prior Art
The advantages of a single controlling element for both accelerating and braking are numerous and have been recognized and appreciated by many inventors since the dawn of motor industry. The most important advantage of a single-pedal control over the conventional two-pedal control is that the driver's foot travels shorter distance when transition from accelerating to braking is desired. As a result less time is needed to start braking after a period of accelerating or maintaining constant speed by means for fueling the engine. Consequently, in case of emergency the time from perception of emergency to engaging vehicle brakes is reduced whereby increasing chances of avoiding an accident or lessening its severity.
Despite great effort none of the prior art has found its way to widespread use mainly because potential advantages of a single controlling element have been overweighed by inherent disadvantages of the proposed mechanisms.
The prior art search has revealed dozens of inventions combining the functions of accelerator and brakes in a single controlling element. Only those which are closest in operational characteristics to my combination control will be analysed here. They are divided into several classes according to the disadvantages they are flawed with. Some of them fit into more than one class; these were included in the class in which the particular drawback is most prominent.
______________________________________ Class 1 Pat. # Granted on Inventor(s) ______________________________________ 1,910,412 May 23, 1929 Edwin G. Staude 2,113,974 April 12, 1938 William Arkley 2,200,685 May 14, 1940 Stanley E. Anderson 2,279,458 April 14, 1941 Jack C. Harkness 2,332,122 October 19, 1943 Isaac Newtown Vaughn 2,453,054 November 2, 1948 Richard Eldridge Whiffen 2,547,593 April 3, 1951 Paul C. Morris 2,627,329 February 3, 1953 Marshall P. Deputy 2,724,469 November 22, 1955 William A Bailey 3,635,316 January 18, 1972 Henry C. Rogers and Fanny L. Rogers ______________________________________
In all of the above inventions the operator's foot is supported by a spring or other resilient means during normal driving, i.e. when the accelerator is applied. To apply brakes, the driver has to act against the supporting spring tension. The supporting spring has to be strong enough to support a foot of even the heaviest driver, so that he/she does not `ride` brakes during normal driving. Potential advantages of a single control elements are overweighed by a substantially greater effort required from the driver to apply brakes.
______________________________________ Class 2 Pat.# Granted on Inventor(s) ______________________________________ 2,024,055 December 10, 1935 Robert P. Moore 2,085,550 June 29, 1937 Edwin G. Staude 2,203,777 June 11, 1940 Fred E Detmers 2,321,614 June 15, 1943 Clinton D. Palmer, William N. Lowe 2,730,214 January 10, 1956 Pauline F. Scott ______________________________________
In these inventions the operator's foot is supported by a yieldable lock during normal driving. Once the initial resistance is overcome the driver no longer has to maintain great pressure on the pedal to keep the brakes applied. The initial resistance of the yieldable lock has to be strong enough to support a foot of even the heaviest driver which makes it hard for a weak driver to apply brakes. Additionally this solution makes it difficult to apply brakes gently--you have to hit the pedal hard to overcome the initial resistance of the yieldable lock. Moreover, they do not prevent applying brakes when the throttle valve is open. Consequently, in an emergency the driver may have the throttle fully open while applying brakes, whereby diminishing the effectiveness of braking.
______________________________________ Class 3 Pat.# Granted on Inventor(s) ______________________________________ 1,907,009 May 2, 1933 Edward A. Rockwell 2,021,859 November 19, 1935 Franklin W. Jarvis 2,042,202 May 26, 1936 Arthur B. Althouse 2,258,627 April 13, 1940 John L. Siesennop 2,411,167 November 19, 1946 Nelson I. Perry 2,738,862 March 20 1956 Kenneth W. England 2,856,042 October 14, 1958 Kenneth W. England 2,936,867 May 17, 1960 nelson I. Perry ______________________________________
In these inventions it is not possible to open throttle valve when brakes are applied, which makes it hard to start the vehicle uphill without the use of an additional (hand) brake. Also, the inventions in this class are complicated, whereby inherently less reliable and more expensive to manufacture than for example the standard two pedal solution.
______________________________________ Class 4 Pat.# Granted on Inventor(s) ______________________________________ 1,489,025 April 1, 1924 William Davis 1,503,939 August 5, 1924 William Davis 2,125,952 August 9, 1938 Nelson I. Perry 2,244,116 June 3, 1941 Lubo Polonec and Anders K. Andersen 2,536,854 January 2 1951 Lester J. Parker 2,787,352 April 2, 1957 Ernest S. Hoobler 2,791,302 May 7, 1957 Noel Albert Christopher 4,237,752 December 9, 1980 Herold V. Hilderbrecht ______________________________________
In these inventions some slidable movement of the pedal is required to actuate different mechanisms, hence the pressure of the driver's foot against the control member is not always perpendicular to the surface engaged by the driver's foot whereby promoting slippage of the driver's foot off the pedal.
The following patents do not seem to fit any of the above classes.
The invention of U.S. Pat. No. 2,677,446 granted on May 4, 1954 to W. K. Hrushow is prohibitedly complex.
The size of the invention of U.S. Pat. No. 3,359,821 granted on Dec. 26, 1967 to R. G Beardsley et. al. makes it unsuitable for automobiles. Also it is relatively complex.
In the invention of U.S. Pat. No. 2,060,731 granted on Nov. 10, 1936 to R. Harroun the pedal travels a very short distance for brakes actuation. This feature renders the invention useless for brakes which are not power assisted as they would require too strong pressure applied to the pedal to brake effectively. Moreover the fine movement of the pedal for brake actuation requires that the driver fine-tune his/her actions to obtain the desired braking power.
Another interesting mechanism is disclosed in U.S. Pat. No. 2,015,,717 granted on Oct. 1, 1935 to Arthur D. Hanratty. There are, however, certain features of this device which act to its disadvantage. These include:
Change in brake lever position does affect the throttle.
To effectively operate the throttle when brakes are applied and at the same time to be able to release brakes easily, it is necessary to press gas fully first.
It is possible to get the pedal stuck in the braking position by slightly opening the throttle when braking.
The device is rather complex, with many moving parts; it employs a rack and pawl mechanism, which is known to require frequent lubrication.